Optical sensing methods and systems for transformers, and the construction thereof

ABSTRACT

Sensing methods and systems for transformers, and the construction thereof, are described herein. Example transformer systems and example methods for constructing a core for the system are disclosed. The example system includes a core with a bottom plate, two or more limbs mounted to the bottom plate and a top plate enclosing the core. At least one of the bottom plate, the limbs and the top plate is formed with a sensing component therein. The sensing component can be mounted to a spacer layer assembled within a stack of laminated layers. The sensing component can be mounted within a path defined within the spacer layer, for example. Methods for detecting operating conditions within the transformer are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/539,766 filed on Aug. 1, 2017, which is incorporated by referenceherein in its entirety.

FIELD

The described embodiments relate to sensing methods, and systemsthereof, for transformers, and the construction thereof. In particular,at least some of the described methods and systems are directed tosensing the operating conditions within a transformer.

BACKGROUND

Faults within a transformer system, such as a power system or reactorsystem, can be difficult to detect in a timely manner. Faults at atransformer can be caused by physical breakdowns, design flaws, andelectrical and/or magnetic flux fluctuations resulting from temperaturevariation (e.g., hot spots) and/or physical stress. These faults canoccur deep within the transformers and can occur fairly quickly,possibly even within minutes. These faults can cause significantfailures within the transformer system and can even cause the system toexplode.

Point sensors can be embedded within the transformer system fordetecting operating condition(s) at a specific location. To capturesufficient data to represent the operating condition of the overallsystem, a significant number of point sensors are required to beinstalled throughout the system. A detection range of the point sensorscan be limited and so, point sensors may not detect nearby faults ifthey occur outside the spatial detection range.

SUMMARY

The various embodiments described herein generally relate to sensingmethods, systems and the construction thereof.

In accordance with some embodiments, a transformer system includes: acore having: a bottom plate; two or more limbs mounted to the bottomplate; and a top plate mounted to the two or more limbs to enclose thecore, wherein at least one of the bottom plate, the top plate and a limbis formed with a sensing component therein; and a winding assembly woundaround each respective limb.

In some embodiments, the at least one of the bottom plate, the top plateand the limb includes at least one sensing layer within a stack oflaminated layers, each sensing layer including a spacer layer with thesensing component mounted therein; and an electrical coupling betweenlaminated layers neighboring the sensing layer.

In some embodiments, the at least one sensing layer includes a sensinglayer, and the sensing layer is positioned at a substantially centralposition within the stack of laminated layers.

In some embodiments, the at least one sensing layer includes two or moresensing layers, and the two or more sensing layers are distributedsubstantially equidistant from each other within the stack of laminatedlayers.

In some embodiments, each sensing layer includes: the spacer layer witha path defined therein; and the sensing component mounted within thepath.

In some embodiments, the path extends along a length and/or a width ofthe spacer layer.

In some embodiments, at least a portion of the path includes anoscillating pattern.

In some embodiments, the sensing component includes an optical fiber.

In accordance with some embodiments, a method of constructing a core fora transformer system includes: forming a core sensing element by:mounting a sensing component to a spacer layer to form a sensing layer;compressing the sensing layer within a stack of laminated layers; andproviding an electrical coupling between laminated layers neighboringthe sensing layer; and assembling the core using at least one coresensing element.

In some embodiments, mounting the sensing component to the spacer layerincludes: defining a path within the spacer layer; and mounting thesensing component within the path.

In some embodiments, defining the path into the spacer layer includescutting the path into the spacer layer. Methods for cutting the path caninclude waterjet or other methods, such as laser or with a ComputerNumerical Control (CNC) router.

In some embodiments, the method further includes defining the pathlengthwise along the spacer layer.

In some embodiments, the method further includes defining a portion ofthe path to have an oscillating pattern.

In some embodiments, the sensing component includes an optical fiber.

In some embodiments, mounting the sensing component within the pathincludes: adhering the optical fiber within the path.

In some embodiments, providing the electrical coupling between thelaminated layers neighboring the sensing layer includes connecting theneighboring laminated layers with a bridge component.

In some embodiments, forming the core sensing element includes: formingtwo or more sensing layers; and providing the two or more sensing layerswithin the stack of laminated layers, wherein each sensing layer iscompressed between two neighboring laminated layers.

In some embodiments, the sensing layer is positioned at a substantiallycentral position within the stack of laminated layers.

In some embodiments, the core includes a bottom plate, two or more limbsmounted to the bottom plate, and a top plate mounted to the two or morelimbs to enclose the core; and at least one of the bottom plate, a limband the top plate includes the core sensing element.

In accordance with some embodiments, a method for detecting operatingconditions within a transformer includes: mounting a sensing componentwithin a core of the transformer; receiving an input optical signal froman optical source; transmitting a version of the input optical signal tothe sensing component, wherein the input optical signal is defined witha carrier frequency at a Brillouin value characterized for the sensingcomponent; receiving a plurality of reflected optical data signals fromthe sensing component in response to an interaction between the sensingcomponent and the input optical signal; and analyzing the plurality ofreflected optical data signals to detect one or more operatingconditions within the transformer.

In some embodiments, applying the input optical signal at the Brillouinfrequency further includes applying a Brillouin Optical Time DomanAnalysis (BOTDA).

In some embodiments, the sensing component includes an optical fiber;and the method includes: forming a core sensing element by: mounting thesensing component to a spacer layer to form a sensing layer; compressingthe sensing layer within a stack of laminated layers; and providing anelectrical coupling between laminated layers neighboring the sensinglayer; assembling the core using at least a core sensing element. Thecore sensing element can include multiple elements, in some embodiments.

In some embodiments, the method includes: organizing the sensingcomponent into a plurality of zones; and analyzing the plurality ofreflected optical data signals to detect the one or more operatingconditions within the transformer includes: receiving a selection of oneor more zones from the plurality of zones; identifying a set ofreflected optical data signals from the plurality of the reflectedoptical data signals received from the one or more zones within thesensing component; and conducting an analysis of the selected set ofreflected optical data signals to determine the one or more operatingconditions at the one or more zones.

In some embodiments, analyzing the plurality of reflected optical datasignals to detect the one or more operating conditions within thetransformer includes: detecting a variation in at least one of the oneor more operating conditions within the transformer.

In accordance with some embodiments, a system for detecting operatingconditions within a transformer includes: a sensing component mountedwithin a core of the transformer; an optical signal processing componentfor: receiving an input optical signal from an optical source;transmitting a version of the input optical signal to the sensingcomponent, wherein the version of the input optical signal is definedwith a carrier frequency at a Brillouin value characterized for thesensing component; and receiving a plurality of reflected optical datasignals from the sensing component in response to an interaction betweenthe sensing component and the version of the input optical signal; and aprocessor for analyzing the plurality of reflected optical data signalsto detect one or more operating conditions within the transformer.

In some embodiments, the optical signal processing component appliesBrillouin Optical Time Doman Analysis (BOTDA).

In some embodiments, the sensing component includes an optical fiber;and the core has: a bottom plate; two or more limbs mounted to thebottom plate; and a top plate mounted to the two or more limbs toenclose the core, wherein at least one of the bottom plate, the topplate and a limb is formed with a sensing component therein.

In some embodiments, the processor operates to detect a variation in atleast one of the one or more operating conditions within thetransformer.

In accordance with some embodiments, a method of constructing a windingassembly includes: forming a sensing coil, the sensing coil including: alower coil portion with a lower groove defined therein, an upper coilportion with an upper groove defined therein, and a bonding layercoupling the lower coil portion with the upper coil portion, wherein thelower and upper grooves form a passage for receiving a sensingcomponent; and winding the sensing coil onto a coil former.

In some embodiments, the sensing component includes an optical fiber.

In some embodiments, the coil former includes one of a former and a coreof a transformer.

In some embodiments, each of the lower groove and upper groove is formedat a substantially central position of the respective lower and uppercoil portions.

BRIEF DESCRIPTION OF THE DRAWINGS

Several embodiments will now be described in detail with reference tothe drawings, in which:

FIG. 1 is a block diagram of an optical sensing system in accordancewith an example embodiment;

FIG. 2A is a block diagram of a control system in accordance with anexample embodiment;

FIG. 2B is a block diagram of a control system in accordance withanother example embodiment;

FIG. 3A is a graph showing a waveform generated by the control system inaccordance with an example embodiment;

FIG. 3B is a screenshot of a waveform generated by the control system inaccordance with another example embodiment;

FIG. 4 is a partial perspective view of a partially constructed windingassembly in accordance with an example embodiment;

FIG. 5A is a perspective view of a partially constructed windingassembly in accordance with an example embodiment;

FIG. 5B is a top cross-sectional view of the partially constructedwinding assembly shown in FIG. 5A;

FIG. 6 is a side view of a winding assembly in accordance with anotherexample embodiment;

FIG. 7 is a top cross-sectional view of a winding assembly in accordancewith another example embodiment;

FIG. 8A is a partial perspective view of a partially constructed windingassembly in accordance with another example embodiment;

FIG. 8B is a partial perspective view of the partially constructedwinding assembly shown in FIG. 8A at a later stage of construction andwith a portion of a coil cut out;

FIG. 8C is a partial perspective view taken from the bottom of thepartially constructed winding assembly shown in FIG. 8B;

FIG. 9A is a partial perspective view of a partially constructed windingassembly in accordance with another example embodiment;

FIG. 9B is a partial perspective view of the partially constructedwinding assembly shown in FIG. 9A at a later stage of construction;

FIG. 9C is a partial perspective view of the partially constructedwinding assembly shown in FIG. 9B at a later stage of construction;

FIG. 10 is a side view of a transformer assembled with two examplewinding assemblies in accordance with an example embodiment;

FIG. 11 is a perspective view of an example transformer assembled withexample winding assemblies described herein;

FIG. 12A is a diagram representing a winding assembly from a topcross-sectional view in accordance with an example embodiment;

FIG. 12B is a diagram representing a winding assembly from a topcross-sectional view in accordance with another example embodiment;

FIG. 13A is a cross-sectional view of an example sensing coil inaccordance with an example embodiment;

FIG. 13B is a cross-sectional view of another example sensing coil inaccordance with another example embodiment;

FIG. 14A is a cross-sectional view of a transformer in accordance withanother example embodiment;

FIG. 14B is a top view of an example center limb for the transformershown in FIG. 14A;

FIG. 14C is a top view of another example center limb for thetransformer shown in FIG. 14A;

FIG. 14D is a front view of a sensing layer for the center limb shown inFIG. 14B; and

FIG. 15 shows an example template of path patterns for an exampletransformer.

The drawings, described below, are provided for purposes ofillustration, and not of limitation, of the aspects and features ofvarious examples of embodiments described herein. For simplicity andclarity of illustration, elements shown in the drawings have notnecessarily been drawn to scale. The dimensions of some of the elementsmay be exaggerated relative to other elements for clarity. It will beappreciated that for simplicity and clarity of illustration, whereconsidered appropriate, reference numerals may be repeated among thedrawings to indicate corresponding or analogous elements or steps.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

During operation, an internal environment of a transformer can changequickly and faults can occur rapidly. Faults within a transformer can becaused by physical breakdowns, design flaws, and electrical and/ormagnetic flux fluctuations resulting from temperature variation (e.g.,hot spots) and/or physical stress. These faults can cause significantfailures within the transformer system and can even cause fire and/orexplosions. It is, therefore, important to detect faults inside thetransformer within a reasonable time and with a reasonable degree ofaccuracy with respect to the location of the fault. The internalenvironment of the transformer can also be harsh due to the exposure tocorrosive chemicals. The sensing systems described herein can facilitatethe detection of these faults.

The transformers described herein include any high voltage devicesformed of a core and windings. Example transformer systems can includepower systems in which the transformer operate to convert voltage andreactor systems in which the transformer operates to absorb a portion ofthe reactive power.

Reference is made to FIG. 1 , which illustrates a block diagram of anoptical sensing system 100.

The optical sensing system 100 includes a control system 120 and asensing component 110. The sensing component 110 can include an opticalfiber 130. The optical fiber 130 may be coupled with a reflector at anend away from the control system 120.

The control system 120 can apply Brillouin Optical Time-Domain Analysis(BOTDA) for monitoring operating conditions at the sensing component110. When applying Brillouin Optical Time-Domain Analysis (BOTDA) tooptical devices, such as the optical fiber 130, a shift within theBrillouin spectrum can represent a temperature and/or strain change atthe optical fiber 130.

The control system 120 includes an optical source 122, an optical signalprocessing component 124 and a processor 126. As shown, the processor126 is in communication with the optical source 122 and the opticalsignal processing component 124.

The optical source 122 can generate an input optical signal that willtravel within the sensing component 110. For example, the optical source122 can include a laser that can generate a continuous output beam, or acontinuous wave. The input optical signal generated by the opticalsource 122 is then directed to the optical signal processing component124. Example optical sources 122 can include a tunable laser source, anda laser diode paired with an optical filter. The optical filter may betunable.

As shown in FIG. 1 , the optical signal processing component 124receives the input optical signal from the optical source 122. Theoptical signal processing component 124 can preprocess the input opticalsignal before transmitting a processed optical signal to the sensingcomponent 110.

The optical signal processing component 124 can include an opticmodulator that can include an electro-optic modulator and/or anacousto-optic modulator for modulating the input optical signal. Theoperation of the optic modulator can be controlled by the processor 126.For example, the processor 126 can define a modulation to be applied tothe input optical signal and can then transmit a correspondingmodulation signal to a pulse conditioning component. The pulseconditioning component can then generate modulation control signals fortriggering the operation of the electro-optic modulator. In someembodiments, the pulse conditioning component can also include amicrowave generator and a DC bias component.

The DC bias component can define certain properties of the modulatedoptical signal, such as a duration of the signal. For example, the DCbias component can be pulsed at low frequency, such as a frequencywithin the kilohertz range, to define the duration of the spacingbetween the pulses to be longer than a time of flight within the opticalfiber 130. In this way, there will be no confusion between the varioussets of optical data signals returning from the optical fiber 130.

In some embodiments, an optical filter can receive the input opticalsignal from the optical source 122 for varying the input optical signal.The optical filter can reduce broadband noise from the optical source122. The optical filter can, in some embodiments, filter the inputoptical signal so that only the Brillouin reflection remains. Forexample, a Bragg filter can be included so that it passes only theBrillouin reflection component of the input optical signal.

An optical amplifier can be included in the optical signal processingcomponent 124, in some embodiments, for amplifying the input opticalsignal, or a version of the input optical signal. An example opticalamplifier includes an Erbium doped fiber amplifier.

The optical signal processing component 124 can include a directionalcomponent for directing the transmission of the input optical signal, ora version of the input optical signal, towards the sensing component110. In some embodiments, the directional component can include anoptical isolator that can prevent unwanted feedback. The opticalisolator can be positioned before or after the optical filter, theelectro-optic modulator, and/or the optical amplifier, in someembodiments.

To facilitate the transmission of the optical signals between theprocessor 126 and the sensing component 110, the optical signalprocessing component 124 includes a circulator for directing theprocessed optical signal towards the sensing component 110, and thendirecting the optical data signal received from the sensing component110 towards the processor 126 for analysis.

In the transmission path between the circulator and the processor 126,various post-processing of the optical data signal may be conducted. Forexample, the optical signal processing component 124 can include anoptical filter, such as a Bragg filter, for varying the strength of theoptical data signal. Other components, such as a photodetector and anamplifier, can also be included in the optical signal processingcomponent 124 for processing the optical data signal before transmittinga processed optical data signal to the processor 126.

Example implementations of the control system 120 are shown in FIGS. 2Aand 2B.

As shown in FIG. 2A, an example control system 120A can include anoptical signal processing component 124A with an optical isolator 150and a circulator 152. The optical isolator 150 can receive an inputoptical signal from the optical source 122 and direct the input opticalsignal towards the circulator 152 while preventing unwanted feedbacksignals from flowing towards the optical source 122. The circulator 152can then direct the input optical signal towards the sensing component110, as well as receive optical data signals from the sensing component110.

FIG. 2B shows another example control system 120B. The control system120B can include an optical signal processing component 124B as shown.The optical signal processing component 124B can include anelectro-optic modulator 160 that receives an input optical signal fromthe optical source 122.

The optical source 122 can be a continuous wave laser. The laser can becontinuously modulated at the desired frequency. The desired frequencycan vary between and including 10 GHz to 13 GHz depending on the type offiber and coating at the fiber. The DC bias component within the pulseconditioning component 166 can also be continuously pulsed within thekilohertz range to generate a low frequency pulses on top of highfrequency modulated signal generated by the laser. The modulated lasercan generate the Brillouin sidebands (e.g., such as 184 a, 184 b shownin FIG. 3A) and the low frequency pulses generated by the DC biascomponent signal allows for the time domain analysis.

The electro-optic modulator 160 can modulate the input optical signal tosquare laser pulses. The square laser pulses, depending on the intendedsensing component 110 and its environment can be within a kilohertz orhertz range. For conducting the Brillouin Optical Time-Domain Analysis(BOTDA), the electro-optic modulator 160 can generate two side bandswith an equal frequency shift around the Brillouin frequency (or themain carrier frequency) corresponding to the sensing component 110.

A pulse conditioning component 166 can include a microwave generator fortuning the frequency shift of the sidebands generated by theelectro-optic modulator 160. The frequency shift of the sidebands isrecorded by the processor 126.

For sensing components 110 in which silica optical fibers are used, theBrillouin frequency is approximately between 10 GHz to 12 GHz. FIG. 3Aillustrates an example waveform 180 of a modulated signal generated bythe electro-optic modulator 160 for an optical fiber characterized witha Brillouin value of approximately 12 GHz. As shown in FIG. 3A, themodulated signal has three peaks. A main carrier peak 182 is generatedby the optical source 122, side peak 184 a is the Stokes component ofthe Brillouin reflection and side peak 184 b is the anti-Stokescomponent.

The electro-optic modulator 160 can then transmit a modulated opticalsignal towards an optical amplifier 162, which can direct a version ofthe modulated optical signal towards a circulator 164. From thecirculator 164, the version of the modulated optical signal propagatesinto the sensing component 110. In an optical fiber 130, for example,the pulses of the modulated optical signal within the center frequency(e.g., main carrier peak 182) interact with a back-reflected Stokessideband. The circulator 164 then receives a reflected data signal anddirects the reflected data signal to a photodetector 170.

As shown in FIG. 2B, a filter component 168, such as a Bragg filter, canprocess the reflected data signal from the optical fiber 130 so thatonly the optical signal within the Stokes band is transmitted to theprocessor 126. FIG. 3B shows a screenshot of an example waveform 190representing a Stokes signal 192 processed by the Bragg filter. Anamplifier component 172 can be positioned between the photodetector 170and the processor 126.

The processor 126 can then record the received Stokes band signal as afunction of its frequency shift and time, relative to each of the squarelaser pulse generated by the electro-optic modulator 160. The timeassociated with the Stokes signal can also correspond to a distancetravelled along the optical fiber 130. Using the recorded Stokessignals, the processor 126 can then spatially resolve an operatingcondition of the optical fiber 130, such as temperature and/or strain.As a temperature of the optical fiber 130 at a particular regionchanges, a resulting Stokes signal returning from that region will vary.

By adjusting the RF modulating frequency, the level of the Brillouinresponse is varied. When the Brillouin signal is affected by externalinfluences, such as temperature, the control system 120 can detect thepeak Brillouin response by sweeping the RF frequency to determine achange in temperature or strain.

In some embodiments, the processor 126 can generate a set ofthree-dimensional time domain waveforms with respect to time, frequencyand power to track the temperature of the various regions of the opticalfiber 130 with spatial resolution controlled by the optical signalprocessing component 124 and the processor 126. The operating conditionsof the transformer in which the optical fiber 130 is mounted can, thus,also be tracked.

As will be described with reference to FIGS. 4 to 15 , the sensingcomponent 110 can be installed within a transformer for monitoring theoperating conditions of the transformer.

During operation, the internal environment of the transformer can changequickly and as a result, faults can occur rapidly. These faults cancause significant failures within the transformer system and can evencause fire and/or explosions. It is, therefore, important to detectfaults inside the transformer within a reasonable time and with areasonable degree of accuracy with respect to the location of the fault.

By distributing the optical fiber 130 within the transformer, thedetection range of the sensing component can be increased. The opticalfiber 130 may, in some embodiments, be wound around a coil former of thetransformer more than once. In some embodiments, the optical fiber 130can be positioned within a core of the transformer. The resultingmeasurement data collected from each location within the transformer canbe increased. The optical fiber 130 is also well insulated and thus, isprotected from the corrosive environment.

The construction of the optical sensing system 100 for transformers caninclude mounting the sensing component 110 to a coil former of thetransformer. The coil former can include the core or the former.

In some embodiments, such as those described with reference to FIGS. 4to 12B, a coil can be wound onto the coil former so that the sensingcomponent 110 becomes positioned within the coil. For example, the coilformer can be a structure on which a coil of the transformer is wound,such as a core or the former. In some embodiments, the sensing component110 can be embedded within the coil former. For example, the sensingcomponent 110 can be positioned within the core.

FIG. 4 is a perspective view of an example partially constructed windingassembly 200.

The winding assembly 200 includes the core 202 around which an opticalfiber 230 and a coil 204 are wound. The optical fiber 230, in someembodiments, can be wound to the winding assembly 200 as multipleseparate segments. Although multiple turns of the optical fiber 230 isshown in FIG. 4 , in some embodiments, the optical fiber 230 can bewound a fewer number of turns around the core 202.

The coil 204 is wound separately from the optical fiber 230. It ispossible that the coil 204 is wound closer to the optical fiber 230 sothat the turns in each of the optical fiber 230 and coil 204 are closerin proximity to each other and, in some embodiments, even in contact. InFIG. 4 , the coil 204 and the optical fiber 230 are alternately woundonto the core 202. In some embodiments, the coil 204 can be wound at oneend or either ends of the core 202, or the coil 204 can be wound ontothe core 202 at every other turn of the optical fiber 230.

The coil 204 shown in FIG. 4 may be a set of secondary coils. A set ofprimary coils can be layered on top of the secondary coils to completethe construction of the winding assembly 200.

By winding the optical fiber 230 and coil 204 separately from eachother, the cross-section of the optical fiber 230 will not be exposed tothe physical pressure exerted onto the transformer as a whole when thecore 202 is being assembled. Protecting the optical fiber 230 fromphysical stress during the construction stage can be important since theoptical properties of the optical fiber 230 are dependent on itsphysical properties. An example transformer will be described withreference to each of FIGS. 10 and 11 .

In the example winding assembly 200 shown in FIG. 4 the sensingcomponent 110 is mounted to the core 202. In some embodiments, thesensing component 110 can be embedded within the coil 204 directly.

For example, in a layer winding formation, a flat sheet of conductivematerial can act as the coil 204. A portion of the coil 204 can be woundto act as the coil former. The sensing component 110 can then be mountedto the initial portion of the coil 204 that is acting as the coilformer, and be wound with the remaining portion of the coil 204 onto thecoil former to form a winding assembly. The sensing component 110 can beprotected by an insulating material, such as tape and/or epoxy.

In some other examples, such as those shown in FIGS. 13A and 13B, thecoil 204 can include a groove formed therein for receiving the sensingcomponent 110.

FIG. 13A shows an example sensing coil 1300 in which a coil 1304 has agroove 1314 for receiving an optical fiber 1330. Due to the increasededges at the interface between the groove 1314 and the optical fiber1330, there will likely be increased turbulent flow at the interface.

FIG. 13B shows another example sensing coil 1350. The sensing coil 1350includes a lower coil 1354 with a lower groove 1364 for receiving aportion of an optical fiber 1380, and an upper coil 1356 with an uppergroove 1366 for receiving the other portion of the optical fiber 1380.The lower and upper grooves 1364 and 1366 can be coupled together toform a passage for the optical fiber 1380. As shown, a bonding layer1360 can couple the lower coil 1354 with the upper coil 1356.

In comparison with the sensing coil 1300, the structure of the sensingcoil 1350 has reduced turbulent flow at the interface between the lowerand upper grooves 1364 and 1366 and the optical fiber 1380. The couplingof the lower and upper coils 1354 and 1356 around the optical fiber 1380also increases the protection of the optical fiber 1380.

In some embodiments described herein, a support element can be mountedto the coil former for supporting the sensing component 110 with respectto the coil 204 and the coil former.

FIG. 5A is a perspective view 300A of an example partially constructedwinding assembly 300 and FIG. 5B is a top cross-sectional view 300B ofthe partially constructed winding assembly 300 shown in FIG. 5A. For theexample winding assembly 300, the coil former is a former 350.

The partially constructed winding assembly 300 in this example has onlybeen constructed to be wound with one turn of an optical fiber 330. Thewinding assembly 300 may be constructed with further turns of theoptical fiber 330. For winding assemblies 300 constructed with one turnof the optical fiber 330, the optical fiber 330 can be wound at anapproximately central location relative to a height of the windingassembly 300.

In the example shown in FIGS. 5A and 5B, a support element is used forpositioning the optical fiber 330 with respect to the former 350. Thesupport element includes a set of support spacers, which are showngenerally at 360.

The support spacers 362 shown in FIGS. 5A and 5B can be formed fromspacers adapted for supporting at least a portion of the sensingcomponent 110. During construction of winding assemblies, spacers can beused to insulate and separate neighboring turns of a coil 204 from eachother. Spacers may be formed of pressed paper, in some embodiments. Toact as a support element, the support spacer 362 is defined with aspacing 364 for receiving the sensing component 110. The spacing 364 canbe formed in various ways and can include a groove, a slot or anopening, for example.

In constructing the winding assembly 300, the former 350 is defined witha plurality of slots, which are shown generally at 352. Each slot 354within the plurality of slots 352 is adapted to receive a support spacer362. The slot 354 can be an opening defined in the former 350 forengagingly receiving the support spacer 362. The set of support spacers360 is mounted to the slots 352.

As shown in FIG. 5A, each support spacer 362 has a spacing 364 forreceiving a portion of the optical fiber 330. The optical fiber 330 ispositioned away from a surface of the former 350. A coil (not shown) canthen be wound onto the former 350 above and below the support spacers362 to form one or more concentric layers around the former 350. As thecoil is wound onto the former 350, the optical fiber 330 becomespositioned within the coil.

FIG. 6 is a side view of an example winding assembly 400.

Similar to the winding assembly 300 shown in FIGS. 5A and 5B, thewinding assembly 400 includes a former 450 as the coil former. Thesupport element for positioning the sensing component 110 with respectto the former 450 includes a set of support spacers, which are showngenerally at 460. The sensing component 110 includes an optical fiber430, which is positioned relative to the former 450 via the spacing ineach support spacers 462. As shown in FIG. 6 , a set of spacers, whichare shown generally at 470, are mounted to the former 450 for separatingeach turn of a coil 404 wound above and below the set of support spacers460.

FIG. 7 is a top cross-sectional view of an example partially constructedwinding assembly 500. The winding assembly 500 includes a former 550 asthe coil former, similar to the winding assemblies 300 and 400. However,unlike the winding assembly 300 shown in FIG. 5B, each of the supportspacers 562 mounted to the winding assembly 500 is defined with twospacings 564 a and 564 b for receiving two corresponding turns, 532 and534, of the optical fiber 530. In some embodiments, the support spacers562 can be defined with more than two spacings 564 for receiving morethan two corresponding turns of the optical fiber 530.

FIG. 8A is a partial perspective view 600A of an example partiallyconstructed winding assembly 600. The coil former in the windingassembly 600 is a former 650.

Unlike the winding assemblies 300, 400 and 500, the set of supportspacers 660 are positioned onto a plurality of ribs, which are showngenerally at 653. A first layer of support spacers 660 a is positionedonto the plurality of ribs 653 and a subsequent layer of support spacers660 b is positioned onto the plurality of ribs 653. Although only twolayers 660 a, 660 b of support spacers 662 are shown in FIG. 8A, morelayers of support spacers 662 can be positioned onto the ribs 654,depending on the design parameters of the winding assembly 600.

The plurality of ribs 653 is formed longitudinally on the former 650.Each rib 654, as shown in FIG. 8A, is spaced from each other. Eachsupport spacer 662 is defined with a spacing 664 for receiving a portionof the optical fiber 630.

FIG. 8B is a partial perspective view 600B of the partially constructedwinding assembly 600 shown in FIG. 8A at a later stage of constructionand with a portion of a layer of the coil 604 cut out, and can bereferred to as a version of the partially constructed winding assembly600′. FIG. 8C shows a partial bottom perspective view 600C of thepartially constructed winding assembly 600′ shown in FIG. 8B.

As shown in each of FIGS. 8B and 8C, the coil 604 is wound onto theformer 650 above and below the support spacers 662. A first layer of thecoil 604 is shown at 604 a and a second layer of the coil 604 is shownat 604 b. For illustrative purposes, the first layer 604 a is cut out toshow the winding of the optical fiber 630 from the first layer 660 a tothe second layer 660 b. FIG. 8C illustrates a bottom view of the secondlayer 660 b of support spacers 662 and the positioning of the opticalfiber 630 with respect to the support spacers 662 and the second layer604 b of the coil 604.

In some embodiments, each layer of the coil 604 can include a set ofprimary coils and a set of secondary coils. The set of primary coils hasa different number of turns than the set of secondary coils, and can bewound concentric to the set of secondary coils.

FIGS. 9A to 9C show another example winding assembly 700 at differentstages of construction. Unlike the winding assembly shown in FIGS. 8A to8C, the winding assembly 700 (similar to the winding assembly 500 shownin FIG. 7 ) is constructed with support spacers 762 with two grooves,764 a and 764 b.

FIG. 9A is a partial perspective view 700A of the winding assembly 700.An optical fiber 730 is shown to be positioned onto a groove 764 b of asupport spacer 762 in a first layer 760 a of support spacers. A secondlayer 760 b of support spacers is also shown in FIG. 9A. The first layer760 a and second layer 760 b of support spacers are mounted to some ofthe ribs 754 on the former 750. Above the first layer 760 a of supportspacers is a first layer 704 a of coil. A second layer 704 b of coil iswound between the first layer 760 a and second layer 760 b of supportspacers.

FIG. 9B is a partial perspective view 700B of the winding assembly 700at a later stage in construction (which can be referred to as windingassembly 700′). As shown more clearly in FIG. 9B, each of the supportspacers 762 includes two grooves 764 a, 764 b for receiving two turns ofthe optical fiber 730. Another partial perspective view 700C of thewinding assembly shown in FIGS. 9A and 9B at a later stage ofconstruction is shown in FIG. 9C (which can be referred to as windingassembly 700″).

FIG. 10 is a side view of an example transformer 800 assembled with twoexample winding assemblies 820 and a core 810 formed of two limbs 802, abottom plate 806 and a top plate 808.

The winding assembly 820 includes a former 850 as the coil former, anoptical fiber 830 positioned on a set of support spacers 860, and a coil804 wound onto the former 850 and between a set of spacers 870.

To construct the transformer 800, each winding assembly 820 is fittedthrough a respective limb 802 and rest on the bottom plate 806. The topplate 808 is then fitted onto the limbs 802 to complete the constructionof the transformer 800.

The core 810, in some embodiments, can be formed with the sensingcomponent 110 integrated therein. An example transformer 1400 in which acore 1410 is integrated with the sensing component 110 is now describedwith reference to FIG. 14A.

The transformer 1400 of FIG. 14A includes the core 1410 with threelimbs, namely a first outer limb 1402 a, a second outer limb 1402 b anda center limb 1402 c. The limbs 1402 a, 1402 b, 1402 c are mounted to abottom plate 1406. A top plate 1408 having top plate portions 1408 a and1408 b is mounted to the limbs 1402 a, 1402 b, 1402 c to enclose thecore 1410.

For illustrative purposes, only the outline of the formers is shown at1450. It will be understood that the formers 1450 need to be installedonto the limbs 1402 a, 1402 b, 1402 c prior to assembling the top plate1408 onto the limbs 1402 a, 1402 b, 1402 c. Although not shown, in someembodiments, the formers 1450 can be provided with any of the formersdescribed herein.

Each of the top plate 1408, the bottom plate 1406 and the limbs 1402 a,1402 b and 1402 c is assembled by compressing a stack of laminatedlayers together. One or more of the top plate 1408, the bottom plate1406 and the limbs 1402 a, 1402 b and 1402 c can be assembled to includea sensing component 110. A core sensing element can refer to any of thetop plate 1408, the bottom plate 1406 and the limbs 1402 a, 1402 b and1402 c that is assembled with a sensing component 110.

FIGS. 14B and 14C show a top view of example center limbs 1402 c and1402 c′, respectively.

FIG. 14B is a top view of an example center limb 1402 c. The center limb1402 c is formed by compressing one or more laminated layers 1422together to form a stack of laminated layers 1420. As shown in FIG. 14B,the stack 1420 includes a sensing layer 1460. The laminated layers 1422neighboring the sensing layer 1460 are connected with electricalcouplings 1412, such as a bridge component.

In the example shown in FIG. 14B, the sensing layer 1460 is positionedat a substantially central position within the stack 1420. In otherembodiments, the sensing layer 1460 can be positioned in a differentposition within the stack 1420. The position of the sensing layer 1460can vary depending on the intended application of the transformer 1400,such as the area of the transformer 1400 that the optical sensing system100 is intended to monitor.

In some embodiments, a core sensing element, such as center limb 1402 cshown in FIG. 14B, can include two or more sensing layers. When multiplesensing layers 1460 are provided, the sensing layers 1460 can be equallydistributed within the stack 1420 or variedly distributed depending onthe area of the transformer 1400 that the optical sensing system 100 isintended to monitor. Increasing the number of sensing layers 1460 canincrease the sensitivity of the measurements collected by the opticalsensing system 100. An example core sensing element with multiplesensing layers 1460 will now be described with reference to FIG. 14C.

FIG. 14C is a top view of another example center limb 1402 c′. Unlikethe center limb 1402 c of FIG. 14B, the center limb 1402 c′ includesthree sensing layers 1470, 1472, and 1474 that are relatively equallydistributed within the stack 1420′. As shown in FIG. 14C, the laminatedlayers neighboring each of the sensing layers 1470, 1472, and 1474 iscoupled to each other with electrical couplings 1412.

FIG. 14D is a front view of the sensing layer 1460. The sensing layers1470, 1472, and 1474 can be analogous to the sensing layer 1460 but withscaled dimensions. As shown in FIG. 14D, the sensing layer 1460 isformed by defining a path 1462 within a spacer layer 1464. The spacerlayer 1464 can be formed of an insulating material, such as fiberglass.In some embodiments, the spacer layer 1464 can be formed of anon-dielectric material, such as steel, in which case the bridgecomponent may not be necessary.

Example fiberglass can include any fiberglass with a high mechanicalstrength and high temperature rating (e.g., 130° C. or higher). Thespacer layer 1464 can be formed of woven fiberglass cloth with an epoxyresin, in some embodiments. For example, the fiberglass used can includeGPO3, Garolite, G10, G11, or similar quality.

When assembling the stacks 1420, 1420′, the spacer layer 1464 is placedonto one or more laminated layers 1422 and a sensing component 1430,such as an optical fiber, can then be mounted within the path 1462. Thesensing component 1430 can be adhered within the path 1462 with epoxy,for example. Additional laminated layers 1422 are then added on top ofthe sensing layer 1460, 1470 to form the stacks 1420, 1420′,respectively.

The path 1462 extends lengthwise along the sensing layer 1460. As shownin FIG. 14D, a portion of the path 1462 can have an oscillating pattern.It will be understood that other patterns may be used depending on theintended application of the transformer 1400.

FIG. 15 shows an example path pattern template 1500 for a core withthree limbs, such as the transformer shown in FIG. 14A.

The template 1500 includes a template 1502 c with a path pattern 1552 cfor a center limb, templates 1502 a and 1502 b with path patterns 1552 aand 1552 b, respectively, for outer limbs, a template 1506 with a pathpattern 1556 for a bottom plate, and a template 1508 with a path pattern1558 for a top plate. Depending on a diameter of the core, the template1500 can be scaled accordingly. As shown in FIG. 15 , a portion of eachof the path patterns 1552 a to 1558 includes an oscillating pattern.Other path patterns can be used for forming the core sensing elements.The template 1500 is illustrative of example patterns. Different pathpatterns may be used depending on the intended application of thetransformer 1400.

The path pattern template 1500 can be used as a guide for defining thepath patterns 1552 a to 1558 into the respective spacer layers. Forexample, using the template 1500 as a guide, a waterjet cuttingtechnique or other similar techniques can be used to cut the pathpatterns 1552 a to 1558 into the respective spacer layers.

FIG. 11 illustrates a perspective view of another example transformer900 constructed assembled with example winding assemblies 950.

In some embodiments, depending on the design of the transformer 800,900, the winding assemblies 820, 950 can be differently constructed. Forexample, the number of turns in the coil may be different, and/or thenumber of limbs can be different.

For monitoring the operating conditions of the transformer, a sensingcomponent 110 mounted to the transformer can be organized into multipledifferent zones. The various different zones enable the processor 126 tofocus the analysis to certain regions within the transformer. Forexample, certain regions within the transformer may be more likely tosustain faults, or the operating conditions in those regions are morelikely to rapidly change and therefore, require more concentratedmonitoring. As a result, the processor 126 may analyze the data signalsreturning from those regions more frequently than the data signals fromother regions. The processing load at the processor 126 can, thus, beredistributed, and unnecessary processing can be minimized.

FIGS. 12A and 12B illustrate different zones that can be defined for thesensing component 110.

FIG. 12A shows a diagram 1000A representing an example winding assembly1000 from a top cross-sectional view.

The sensing component 110 mounted to the winding assembly 1000 is anoptical fiber 1030. The optical fiber 1030 can be wound around a coilformer 1050 as shown in FIG. 12A. For tracking the optical data signalsreceived from the optical fiber 1030, the processor 126 can define theoptical fiber 1030 into multiple zones 1080 with reference to thecross-sectional area of the coil former 1050. For example, as shown inFIG. 12A, a first zone 1080 a can be defined for a first region of thecoil former 1050, a second zone 1080 b can be defined for a secondregion of the coil former 1050, a third zone 1080 c can be defined for athird region of the coil former 1050, and a fourth zone 1080 d can bedefined for a fourth region of the coil former 1050.

FIG. 12B shows another diagram 1000B representing the winding assembly1000.

Unlike the organization of the zones 1080 shown in FIG. 12A, theprocessor 126 can define the optical fiber 1030 into zones 1082 based onsegments of the optical fiber 1030. For example, as shown in FIG. 12B,the processor 126 can define a first segment of the optical fiber 1030as a first zone 1082 a, a second segment of the optical fiber 1030 as asecond zone 1082 b, a third segment of the optical fiber 1030 as a thirdzone 1082 c, a fourth segment of the optical fiber 1030 as a fourth zone1082 d, a fifth segment of the optical fiber 1030 as a fifth zone 1082e, a sixth segment of the optical fiber 1030 as a sixth zone 1082 f, anda seventh segment of the optical fiber 1030 as a seventh zone 1082 g.

It will be understood that the size of each of the zones 1080, 1082 canbe varied with user preferences and/or design parameters of the overalloptical sensing system 100.

It will be appreciated that numerous specific details are describedherein in order to provide a thorough understanding of the describedexample embodiments. However, it will be understood by those of ordinaryskill in the art that the embodiments described herein may be practicedwithout these specific details. In other instances, well-known methods,procedures and components have not been described in detail so as not toobscure the embodiments described herein. Furthermore, this descriptionand the drawings are not to be considered as limiting the scope of theembodiments described herein in any way, but rather as merely describingthe implementation of the various embodiments described herein.

It should be noted that terms of degree such as “substantially”, “about”and “approximately” when used herein mean a reasonable amount ofdeviation of the modified term such that the end result is notsignificantly changed. These terms of degree should be construed asincluding a deviation of the modified term if this deviation would notnegate the meaning of the term it modifies.

In addition, as used herein, the wording “and/or” is intended torepresent an inclusive-or. That is, “X and/or Y” is intended to mean Xor Y or both, for example. As a further example, “X, Y, and/or Z” isintended to mean X or Y or Z or any combination thereof.

It should be noted that the term “coupled” used herein indicates thattwo elements can be directly coupled to one another or coupled to oneanother through one or more intermediate elements.

The embodiments of the systems and methods described herein may beimplemented in hardware or software, or a combination of both. Theseembodiments may be implemented in computer programs executing onprogrammable computers, each computer including at least one processor,a data storage system (including volatile memory or non-volatile memoryor other data storage elements or a combination thereof), and at leastone communication interface. For example and without limitation, theprogrammable computers (referred to below as computing devices) may be aserver, network appliance, embedded device, computer expansion module, apersonal computer, laptop, personal data assistant, cellular telephone,smart-phone device, tablet computer, a wireless device or any othercomputing device capable of being configured to carry out the methodsdescribed herein.

Various embodiments have been described herein by way of example only.Various modification and variations may be made to these exampleembodiments without departing from the spirit and scope of theinvention, which is limited only by the appended claims.

We claim:
 1. A transformer system comprising: a core having: a bottomplate; two or more limbs mounted to the bottom plate; and a top platemounted to the two or more limbs to enclose the core, wherein at leastone of the bottom plate, the top plate and a limb is formed with asensing component therein, and at least one of the bottom plate, the topplate and the limb comprises at least one sensing layer within a stackof laminated layers, each sensing layer comprising a spacer layer withthe sensing component mounted therein; an electrical coupling betweenlaminated layers neighboring the sensing layer; and a winding assemblywound around each respective limb.
 2. The transformer system of claim 1,wherein: the at least one sensing layer comprises a sensing layer, andthe sensing layer is positioned at a substantially central positionwithin the stack of laminated layers.
 3. The transformer system of claim1, wherein: the at least one sensing layer comprises two or more sensinglayers, and the two or more sensing layers are distributed substantiallyequidistant from each other within the stack of laminated layers.
 4. Thetransformer system of claim 1, wherein each sensing layer comprises: thespacer layer with a path defined therein; and the sensing componentmounted within the path.
 5. The transformer system of claim 4, whereinthe path extends along a length of the spacer layer.
 6. The transformersystem of claim 4, wherein the path extends along a width of the spacerlayer.
 7. The transformer system of claim 4, wherein at least a portionof the path comprises an oscillating pattern.
 8. The transformer systemof claim 1, wherein the sensing component comprises an optical fiber.